Genuine Willys Jeep vehicles have a data plate on the glovebox door. The data plate shows information including the manufacturer, model, serial number and the delivery date of the vehicle. It may be necessary to remove a layer of paint to read the plate.

Check inside the left frame rail behind the bumper for a small zinc tag. Two small rivet pins hold the tag. It should show a serial number in the form of two letters followed by six numbers with no spaces in between. If the vehicle is genuine, the number should match the one on the glovebox door.

The engine also has a serial number. Find it on a rounded boss on the right side of the engine, near the front of the block, below the head. Although it is in the exact same format, the engine serial number does not match the numbers on the glovebox or inside the left frame rail.

Find the final serial number on the body tub of the vehicle. It is on a triangular brace on the driver's side toeboard gusset. This serial number consists only of six numbers and should not match any of the previous numbers.

If a Willys Jeep has all the four serial numbers, and if only the first two are the same, it is very likely that the vehicle is genuine. Exercise good judgment when making a purchase decision.